JPS60182559A - Cassette type magnetic tape device - Google Patents

Abstract

PURPOSE:To improve the processing efficiency to a reading error by recording a data block consisting of the ID information, the real data and an error detecting signal and a data correction block on a data track of a recording medium and at the same time recording a marker signal on a marker track. CONSTITUTION:An audio cassette tape CMT10 contains a data track TD13 and a marker track TM14. Then 32 data blocks consisting of the ID20, data 21 and CRC characters 22 and four data correction blocks are recorded to the TD13 in the form of a frame. While a marker 18 is recorded to the TM14 in response to each frame head part. A CMT controller 32 is connected to a host computer H- CPU, and the record/reproduction is controlled for both TD13 and TM14 by amplifiers 34 and 35 as well as 36 and 37. The reading position is controlled by the majority logic of the ID20 and the marker 18. Then the CRC22 of the data block is read and the data producing an error is corrected by an error correction code of the data correction block. Thus the processing efficiency is improved for a cassette type magnetic tape device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a cassette-type magnetic tape device for recording and reproducing digital information on an audio cassette-type magnetic tape.

[Technical background of the invention and its problems]

In recent years, data recording means using an audio cassette magnetic tape (hereinafter referred to as CMT) as a recording medium has been widely used in small-sized computers such as personal computers. The conventional data recording format on the CMT at this time is shown in FIG. In the figure, 1 indicates Norian pull, real data, CRC (Cyclic Redundancy).
Check) Data block consisting of character afterter and postamble, 2 is serial/pull, 16 bits “0”
#Control block consisting of data and postamble, 3
is the block interval IRG (Inter Record
Gap).

In conventional data recording/reproducing means employing such a recording method, the control block 2 is used to locate the beginning of data when reading data. At this time, if an error is detected by the CRC check during data reading, the CRT can be reread by at least the control block located at the front of the data block where the error occurred.
Rewinding is controlled while determining the read data up to the RQ position, and the control block and subsequent data block in which an error has occurred are reread. Therefore, in the conventional method, when an error occurs in a data block, rewinding control for rereading the data block becomes extremely complicated and takes a lot of time. Furthermore, the conventional method has the disadvantage that when a reading error occurs in the control block 2, the subsequent data block 1 cannot be read.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and it corrects errors in the data read shell, and retries uncorrectable errors easily and without waste.
It is an object of the present invention to provide a cassette type magnetic tag device that can be operated with high reliability.

[Summary of the invention]

The present invention provides a data recording device using an audio cassette magnetic tape as a recording medium, wherein the recording medium is provided with a data track and a marker track, and the data track includes ID information, actual data, and an ib detection code. n
IRG is a data group (record) consisting of a data frame of a certain length, in which one frame consists of Xm (for example, 32) data blocks and m (for example, 4) data correction blocks consisting of error correction codes. Hang it.

A specific marker signal is recorded on the marker track at regular intervals corresponding to the head of each frame. When reading data, the data recorded on the data track is read out based on the marker signal recorded on the marker track, and a read υ error is detected using the error detection code of the read block. The error correction code of the data correction block performs error correction of read data with errors. For uncorrectable errors, a retry is performed by rewinding only one frame including the error data block based on the marker position. Data reading position control is performed based on ID information and marker count information, and the ID is determined by majority logic of ID information of the same content recorded in different data blocks within the same frame.

By employing such a recording and reproducing means, it is possible to significantly reduce unnecessary operations associated with read shelling, and data read operations can be executed efficiently and with high reliability.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Second
The figure shows records in one embodiment of the present invention.

The format is shown in the figure, where 10 is a cassette tape (hereinafter referred to as CMT), 11 is a transparent part of GMTlo, and 12 is a prefix blank part. 13 is a data track (TD) using a right channel track, and 14 is a marker track (TM) using a left channel track. 1
5 is a record that is one recording unit of data, 1
6 is record 15. . Each record 15°... is a frame 17,... which forms a data unit of a certain size.
Karanashi, each frame 17. ..., the marker track 14 has a specific marker (approximately 300 Hz here).
IO cycle)18. ... is recorded. In addition, the above I
RG 16 also has the same size as frame 17, and marker 18 is added in the same manner as frame 17. Each frame 17°... is 36 blocks + 101 each
4'-1#...+35, each block is 5YNC (synchronization byte) 1, except for some blocks described below.
9, ID20.3 indicating frame position on GMT 10
2 bytes of data (actual data), 2 bytes of CRC
Consists of 22 characters, etc. The ID 20 indicates a marker number (ivt) unique to the marker 18 corresponding to the frame in which the block is included, and has the same content (same marker number) in each frame. The marker number at this time is marker 1 at the beginning of marker track (TM) Z 4.
8f Consecutive numerical order starting with the youngest number (M1+M2*
...) is attached. Also, CRC character 22
is 5YNCI 9, ID section 20, and data 2
This is an error detection code created based on 1. Also, each of the above 7 frames 17. 36 blocks inside +0°4P
1. ...32 blocks out of 35+0°41
,...+-31 are data blocks in which actual data is recorded in the data section 21, and the remaining four blocks 4P32
．． +33. Reference 34. +35 is a correction data block in which error data correction data is recorded. This corrected data block = IP32°≠33. ≠34. Of the 35,
Block 32 is data block +O, +4',
+8,...+, exclusive OR of 28, block 33
is data block +1. +5. ≠9. ...+29 exclusive OR, block +-34 is data block≠2.
+6°+10. ... +30 exclusive OR, blocker 35 is data blocker 3. 7, -#=11
.

...+31 exclusive OR. This corrected data block +32. ≠33. ≠34. +35 is not provided with an ID.

FIG. 3 is a block diagram showing the hardware configuration of a cassette type magnetic tag device in one embodiment of the present invention. In the figure, 31 is a cassette tape mechanism (hereinafter referred to as CMT-D).
data track (T) on 0MT10.
D:) Two recording and playback heads are installed to enable simultaneous recording and playback for Zs and Marker Track (TM) J4, and a forward/reverse CMT called the so-called -start song selection function. It has functions equivalent to commercially available stereo cassette decks, including high-speed playback functions. 32 is a cassette chip controller (hereinafter referred to as CMT-C) constructed using a 1-chip microcomputer, and a system bus 3
3 to the upper host computer (hereinafter referred to as H-CPU)
). 34 and 35 are the right channel recording and playback amplifiers, here the data track (T
D) Used for recording and reproduction of 13. 36 and 37 are recording and playback amplifiers for the left channel, which are used for recording and playback of the marker track (TM) 14 here. 38 is C
These are various command signal lines for recording, playback, etc. sent from the 114T-C32 to the CMT-DM s1.

Here, the operation of one embodiment will be explained with reference to FIGS. 2 and 3. When the CMT-C 32 receives a data reading command from the I(-CPU), it issues a run command to the CMT-DM s 1 and waits (about 8 seconds) until the CMT 10 passes the prefix blank section 12 ( Here, CMT J
Assume that O is rewound). After the prefix blank section 12 has passed, the marker 18 is written on the marker track (TM) 74, and the data is written on the data track (TD) 13 in the format shown in FIG. 2 of the cell 3. At this time, CMT-C32 has ID20 and CRC character 2.
2, and correction data blocker 32. +33. Add +34°+35 to the data. Also, CMT-C32.

I(-The number of bytes given by the CPU is 1 frame (1
296 bytes), generate dummy block data and write it, making sure that one frame is 36 blocks + 0. ≠1. ...+35. Each marker track (TM) 14 has 7 frames, 1
7. A marker 18 is recorded corresponding to the beginning of . Also, I(-one recording unit from the CPU, that is, record 15
IRQ 16 is provided for each IRG J
6 has the same length as the frame 17, and the marker 17 is attached like the frame. Furthermore, within each block +0.41°, a marker number starting from the beginning of CMT J O is recorded as ID20. For example, each I of the data block of the first frame + (1,, $1...+31)
D20... are the youngest marker numbers (Ml) (i.e. blocks in the same frame≠O, +1...
・+31 has ID2o with the same content).

The data written on the CMT 10 as described above is reproduced overnight as described above.

First, the H-CPU instructs the CMT-C 32 to move CMT lO to the position of the frame to be read. CMT-Cs,? is always the current commercial
T position (i.e. ID, '7; marker number of the corresponding frame)
Based on this, the distance (how many markers are there) and direction (forward/reverse) to the target frame can be determined. C
If the target location is far away, the MT-C32 uses the high-speed playback function to play back the CMT-10 at high speed and then counts the markers 18. Stop high-speed playback before the desired location, and while playing CMT 10f at normal speed, check the count value of marker 18 and ID20f, and check that the IDf one position before the requested ID has been read. Stop CMT l Off with ζro.

Next, I(-CPU uses CM to read the required number of bytes.
Issue a command to T-C32. 'cMT-c s 2 is as follows (
7) From the marker detection, the data recorded on the data track (TD) 13 is read out, and only the actual data 21 of each frame 17 is extracted and sent to the I-CPU.

During this reading process, the CRC of each block is checked, and if error 9 is detected, the CMT-C 32 performs the following operations. That is, the frame containing the erroneous data block is read, and the corrected data block number 32, +3 is read.
The data is corrected using the correction data of 3, +34, and +35. For example, if a CRC error is detected in data block +O, every 4 blocks (-#-4°4=8...) from that block +O, the corrected data block number 3
2-1 is taken, and the result is inverted and becomes the value of Rough Lock+O (this is a method known as the single erasure method). Furthermore, during the above CRC check, if a CRC error occurs in two or more every fourth data block, it cannot be corrected using the single erasure method, so the CW-C32 uses ChlT-10 until the beginning of the frame. Execute full rewind and reread. That is, CMTJ (7) is run in reverse, rewinded until marker 18 is detected, and after passing the marker, C1ViT 10
Stop and try loading again. Furthermore, at the time of data reading at 9 o'clock, if a reading error occurs in the ID20 section, reading the data itself becomes impossible, so the following preventive measures are taken. That is, CMT-032 has ID
is determined using both the count value of the marker 18 and the ID 20 section of the data block (+1). I
D 20 As mentioned above, the data is distributed and recorded in each data block (Olsu 1... Temple 31) within one frame, and the ID is determined by majority logic by reading all of them. . This makes it possible to prevent incorrect ID information from being obtained and improve the reliability of data reading.

Furthermore, if the count value of the marker 18 and the ID information determined by the majority logic are different, the entire count information of the marker is corrected based on the entire ID information. Therefore, even if the count number is incorrect due to noise on the marker, it can be corrected.

In this way, the marker 18 of the marker track (TM) 14
．． ... and the ID determined by the majority logic of the IDs distributed in the data blocks ($0.+1....+31) of the data track (TD) 13 (JT
Since the position of J o is determined, even if an error occurs when reading data, reading on 0MT10 will not be erroneous. Further, since the unit of error correction (frame) and the unit of ID information (marker) are the same, a retry when correction is impossible can be easily carried out by rewinding by one marker. Moreover, only high-speed reading is possible based on the marker information. Furthermore, since the marker/ID information corresponds 1:1 to the physical position of the CMT 10, the remaining length of the CMT 10 can be easily managed based on this information.

By recording and reading data using the above-mentioned recording and reproducing means, it is possible to greatly reduce wasteful operations associated with reading shells, and to make data reading operations efficient and highly reliable. It can be executed with dignity.

〔Effect of the invention〕

As described in detail above, according to the cassette-type magnetic thesis apparatus of the present invention, all errors in data reading errors are corrected, and in the case of uncorrectable errors, the retry operation is performed simply and without waste. This allows the reading operation to be performed efficiently and with high reliability by significantly reducing wasted operations associated with reading errors.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a conventional recording format with 7 formats, FIG. 2 is a diagram showing a recording formatter in an embodiment of the present invention, and FIG. 3 is a block diagram showing the hardware configuration in the above embodiment. 10...Cassette Q f (CMT), 13...
Data track (TD), 24... Marker track (
TM), 15...Record, 16...IRQ,? 7
...Frame, 18...Marker, 19...5YN
C (synchronous byte), 20...ID, 22...CRC
Character, 31...Cassette tape mechanism (C
MT-DM), 32... Cassette tape controller (GMT-C), 34. 36... Recording amplifier, 35.
37...Reproduction amplifier.

Claims (1)

[Claims] In a data recording device using an audio cassette type magnetic tape as a recording medium, the recording medium is provided with a data track and a marker track, and the data track is provided with an I.
A data frame of a certain length is recorded in which one frame consists of nXm data blocks consisting of D information, actual data, and an error detection signal, and m data correction blocks consisting of an error correction code. means for recording a specific marker signal at regular intervals corresponding to the head of each frame; and means for reading and controlling the data frame recorded on the data track based on the marker signal recorded on the marker track. , a means for determining the IDi of the corresponding frame based on majority logic of ID information provided in each data block in the data frame, and a means for determining the IDi of the corresponding frame based on the determined ID content and the count value of the marker signal. A means for controlling a read position value and an error detection code of the read data block detect a read sheller, and an error correction code of the data correction block performs error correction of the read data accompanied by an error. A cassette type magnetic tape device comprising: means.